1 / 39

Auditory Illusions Phy103 Physics of Music

Auditory Illusions Phy103 Physics of Music . J. S. Bach's canon per tonus.

jatin
Download Presentation

Auditory Illusions Phy103 Physics of Music

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Auditory IllusionsPhy103 Physics of Music

  2. J. S. Bach's canon per tonus A very famous example of an endlessly rising melody is the canon per tonus from Johann Sebastian Bach's Musical Offering. The melody rises two half-tones each time the canon is repeated (this should illustrate the rising glory of Frederick the Great to whom the Musical Offering was dedicated). The canon starts in C minor. After the first run it ends in D minor, so the second turn begins two half-tones higher than the first one. When the canon is repeated further, it begins in: c1, d1, e1, f#1, g#1, bb1, c2, d2.

  3. Canon circularis per tonos (Bach)A musical offering

  4. Descending Pitch Illusion http://asa.aip.org/demo27.html

  5. Falling bells • Pitch is actually rising even though it sounds like it is falling From: http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/

  6. Endless rising pitches • Each tone contains separations 7/6 of an octave with an envelope that is fixed • Each tone is shifted by 100 center or 1 semitone

  7. Opening song from anime series GunXsword

  8. A Melody of Silences http://www.kyushu-id.ac.jp/~ynhome/ENG/Demo/illusions.html c2000 Yoshitaka Nakajima

  9. Reflection as a compositional theme • Bartok “Subject and Reflection”, Mikrokosmos, vol 6, #141 played by Jeno Jando • Can your ear pick out the reflective tonal symmetry without seeing the music? • Two melodies played one goes up while the other goes down and vice versa

  10. Now with the music

  11. Now with the spectrum? • Is the reflective tonal symmetry obvious in the spectrum? • Compare how easy it is to SEE this pattern compared to how easy it is to HEAR this pattern

  12. Earthquakes from somewhere in Ethiopia – Cindy Ebinger BOVE • Original file sampled to 50Hz • We multiplied by 400 to 20KHz • 2 hours of data reduced to 18s reversed No time reversal symmetry in hearing

  13. Can we pick out time reversal symmetry (tune followed by itself played in reverse order)? Without the music Anton Webern, Opus 27

  14. Reflection in time-- now with the musicAxis of symmetry is a timeExample from Larry Solomon)Anton Webern, Opus 27

  15. Sensory Integration Illusion • What you see affects what you hear • McGurk effect • Music dubbing http://www.youtube.com/watch?v=aFPtc8BVdJk

  16. Gap Transfer illusion • A bounce is often perceived in the gliding tones • http://www.kyushu-id.ac.jp/~ynhome/ENG/Demo/2nd/01.html Figure and clip by Yoshitaka Nakajima

  17. More on Gap-Transfer Illusion • Often perceived the same Figure and clip by Yoshitaka Nakajima

  18. Split off effect • The listener typically perceives one long tone, which rises and then falls, and a short tone in the middle.   Figure and clip by Yoshitaka Nakajima

  19. More on the split off effect Figure and clip by Yoshitaka Nakajima

  20. More on split off effect Figure and clip by Yoshitaka Nakajima

  21. Streaming • When do two alternating pitches sound like one galloping sound? ASA demo 19 • Yodeling - apparent motion in music Cook demo 33

  22. fast slow Phantom Melodies • From: http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/ • Christian Sinding’s Frühlingsrauschen (“Rustle of Spring”) original recording: www.classicalmidi.co.uk / Slow recording courtesy of Karle-Philip Zamor)

  23. Fast rhythm even in presence of timbre variations can lead to hearing groups of sounds as single sounds“perceptual groupings”

  24. Overlapping piano tones • forward • backward overlaps aren’t really heard

  25. Illusory Continuity • Speech is heard and understood despite noise interruptions Figure and clip by Yoshitaka Nakajima

  26. Temporal Induction of Speech Interrupted by cough Interrupted by silence From New Scientist. Music special: Five great auditory illusions 24 February 2008 by Michael Marshall

  27. Pitch depends on partial frequencies • Butler example 3.5b • Second of each pair has partials 10% sharp. Perceived pitch change depends on frequency

  28. Timbre depends on frequency • First tone has partials 1,2,3,4,5 • Second tone has partials 1,3,5,7,9 • Difference in timbre depends on frequency of fundamental • Butler example 3.5a

  29. A Discontinuous Change in Time Perception Caused by Time-Shrinking • When the difference between the first and the second duration is up to about 100 ms (the sixth pattern), 'time-shrinking', i.e., the second duration is under-estimated

  30. Timing and music Scott Joplin’s The Peacherine • MIDI from http://www.geocities.com/BourbonStreet/2783/sjmidi.htm • Played by Dick Hyman Joplin sounds pretty good in MIDI --- it was played on piano rolls

  31. Quickening Beat Tempo appears to be quickening From: http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/

  32. Combination tones! • Listening example 4.5 Butler. • Only 440 and 660 Hz played, but sometimes can hear a 220 Hz signal (difference) in addition to the other two. • Lower tone is manufactured by your ear/brain

  33. Stereo Auditory illusions • Here I have focused on illusions that don’t involved stereo --- however Diana Deutsch has a series of very interesting stereo illusions. Alternating pitches between ears often perceived as continuous patterns

  34. Chromatic illusion

  35. Deutsch’s Tritone paradox • A tritone is two pitches ½ an octave apart (e.g. C to F#) • One pair of tritones is followed by another. • The listener is asked to judge whether the tones ascend or descend • Musicians often disagree

  36. Tritone paradox • Transposition often causes one listener to change his/her mind even though music when transposed is perceived as the same • Most listeners have a preferred orientation for the pitch circle in perceived tritones--- a form of absolute pitch that every listener has • Listeners from different cultures can disagree on their pitch orientation

  37. Zwicker Tone • Noise with a gap. A tone can be heard following the noise. • The gap should be about the size of the critical band. • I tried this but could not get the illusion to work. Perhaps needs to be done in a quiet environment.

  38. Expectations • The unresolved leading tone that ends one of the movements of Iphigenia in Brooklyn (PDQ). Looking for the clip! • Phantom Melody, try Novacek, Perpetuum Mobile, Violin + Piano arrangement

More Related